According to Memory Alpha's original in Universe Timeline, the story sequence is:
Turnabout Intruder : All Our Yesterdays : Fight or Flight.
In the Remastered Episodes Chronology, the release sequence is
And the Children Shall Lead : All Our Yesterdays : A Piece of the Action.


Enterprise arrives in the Beta Niobe system whose star will go nova in three and a half hours. When they find that all inhabitants of the planet Sarpeidon inside that system have vanished, Kirk, Spock and McCoy beam down to what seems to be a library of the planet's history. There they meet Mr. Atoz, who asks them to select a period of interest and shows them a machine called the Atavachron.

After viewing a recording, Kirk inadvertently steps through a time portal and finds himself in what is the planet's equivalent to Earth's 17th century. He is being accused of witchcraft, but he receives help from a man who himself came from the future. Kirk finds an exit and returns to the library.

Meanwhile Spock and McCoy, who were trying to find the captain, have ended up in Sarpeidon's ice age. They get help from a lonely woman named Zarabeth, who was exiled to that era. Spock somehow reverts to an emotional state of ancient Vulcans, and he falls in love with Zarabeth. Only because of McCoy's insistence they find the way back to the library, just before the planet is destroyed. Zarabeth, however, has to stay behind, because her physiology has been altered by the Atavachron prior to her transfer to that time.

Errors and Explanations

The Nitpicker's Guide for Classic Trekkers

Plot Oversights

  1. Zarabeth wearing a skimpy outfit in the caves. Perhaps the hot springs make the caves too warm for her to wear the full length fur robe.
  2. Spock tells Zarabeth that he comes from a place "millions" of light-years away. The Milky Way is approximately 100,000 light-years in diameter - so "millions" of light-years would place Vulcan well outside the galaxy (contrary to Star Trek canon). This may be a sign of the mental regression he suffers as a side-effect of time travel.[N 1]

Continuity and Production Problems

  1. When Spock and Zarabeth are talking, then Spock turns to see McCoy standing at the cave entrance, we hear McCoy say "You've been dishonest with me, Spock," but his lips don't move.McCoy could be a ventriloquist.[N 2]

Internet Move Database

Character error

  1. When Spock tries to use his phaser to warm a boulder at the base of the ice cliff, it doesn't work - presumably because phasers didn't exist in that time period. But when he lays McCoy out in Zarabeth's cave and examines him, the doctor's medical tricorder seems to work just fine.Perhaps Zor-kahn, the tyrant who exiled Zarabeth, arranged for the time portal to disable obvious weapons as part of the punishment, without harming other equipment.

Plot holes

  1. When the prosecutor is talking to Kirk, the mort (female thief) in the next cell accuses Kirk of being a witch. The constable confirms this, saying that Kirk talked to unseen spirits, one of which he called "Bones". Even though Kirk did address Dr. McCoy as Bones through the unseen time portal, the constable was not present when he did.[N 3] The constable could have been out of view but within earshot when Kirk called out to McCoy.

Fandom Contributions

Plot Holes

  1. User This episode is annoying due to fact that at time stamp 5:45 Captain Kirk failed to properly introduce themselves as they were from the Enterprise a Federation star ship. Of course, then there would have been no journeying off to any chosen past, as then Mr Atos would have understood that they do not belong there. My problem is that everything hinges off the fact that Captain Kirk did not introduce themselves as the catalyst and not something more substantial. I.e. remember when Dr. McKoy went back in time as he was not well at the time in different episode. This was more realistic scenario in my opinion. So why did they fail to do something more convincing as the catalyst and problem?? Maybe Kirk expected Atoz to instantly realise they did not belong there just by looking at their uniforms.

Continuity Errors

  1. User When Kirk goes through the portal he has his phaser. When he comes phaser. It was most likely confiscated when he was arrested, and never returned.


  1. Listed under Character errors in the Internet Movie Database entry
  2. Listed under Audio/visual unsynchronised in the Internet Movie Database entry.
  3. Mentioned under Great Lines in the Classic Trek Nitpicker's Guide entry..

The Original Series Season 3
Spectre of the Gun I Elaan of Troyius I The Paradise Syndrome I The Enterprise Incident I And the Children Shall Lead I Spock's Brain I Is There in Truth No Beauty? I The Empath I The Tholian Web I For the World Is Hollow and I Have Touched the Sky I Day of the Dove I Plato's Stepchildren I Wink of an Eye I That Which Survives I Let That Be Your Last Battlefield I Whom Gods Destroy I The Mark of Gideon I The Lights of Zetar I The Cloud Minders I The Way to Eden I Requiem for Methuselah I The Savage Curtain I All Our Yesterdays I Turnabout Intruder
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